Co-Bot Plus Camera Doubles Shop Throughput

Precision machine shop programs its way around a bottleneck with the help of a robot and Plug + Play wrist camera

WALT Machine Inc. in Lumberton, Miss., specializes in high-precision milling and turning of aluminum and titanium parts for optical systems. Each spring, it is presented with a similar challenge: deliver about 6,000 camera housing in about two months, a job it works to complete without adding to its machining capacity.

One might expect that being able to deliver this order on time would require WALT Machine president Tommy Caughey to hire a full-time CNC machine operator. But, by the time the new employee is fully trained and operational, the parts are almost delivered and the extra service time will be unnecessary.

To deal with the short-term rise in production volume, Caughey started to consider a robotic system. “I saw Universal Robots at four or six years ago, and I found it interesting: a robot that does not require any extra stuff, like jigs for example. I thought, ‘That's where we needed to go one day.’ "

But Caughey knew he needed either a vision system or a conveyer to pick up the unfinished parts from a table, to deliver the parts for finishing. “Everyone told me that it's a very difficult process, that you need to have a person in your shop to do it,” he recalled.

Robotic automation may be intimidating for someone who has never touched a robot. Caughey is one of those entrepreneurs who started from scratch with his first robot. “I've programmed CNC machines and G-codes for 10 years, done XYZ positional and spatial stuff, but never explored robotics. When I got the robot, I did a little reading and it was pretty simple.”

As for the vision system, Caughey was impressed by the Robotiq Wrist Camera teaching methods. “You take your part and set it on the surface where you want it to be picked up, and you take four snapshots of it in four different orientations. Or, if it’s something simple, like a rectangular or a circular blank, you just set the dimensions of what you are picking and it knows.”

The next step is to put 15 to 20 of the same un-machined parts on the table within the camera’s field of view. The robot then rotates and looks over the table, takes one snapshot to see all the parts.

For more accurate picking, the robot gets closer and takes another snapshot of the part it is about to pick. After that, the robot places the part into the vice in the CNC machine. Then, it sends a signal to the Haas CNC machine to press the start button.

“It is so easy,” Caughey added. “We don't even have to teach waypoints because it only needs to look on this table for parts. We don't need a conveyor or any special fixturing. If you change parts, you just need to tell Arthur (the name of WALT Machine’s co-bot, from Universal Robots) that you are looking for a different part, and change the two-finger gripper’s closing set-up. It's pretty simple. There isn't a lot of changeover, so that's why I like the camera-gripper combo.”

One of the main advantages of automated machine tending is the ability to schedule production during the shop’s off-hours. In June 2016, Robotiq — a developer of grippers, sensors, and other end-of-arm collaborative devices — released its Plug + Play Wrist Camera, made exclusively for Universal Robots. For Caughey, it was a game changer.

“I didn’t need a vision expert anymore," he said of the device, which uses vision technology to learn movement patterns. “I could do it myself. I bought the camera, and it’s super simple. It takes about 10 minutes and your part is taught.”

It takes 30 to 45 minutes to machine one side of a camera housing for the big order. Working an eight-hour day it takes several weeks to produce the order with one machine, and WALT Machine could not tolerate such bottleneck in its workflow. “So, being able to run 15-20 hours a day and not having to hire anyone else is a major plus for us,” Caughey said.

Doubled Production and Top Quality — Since WALT Machine Inc. bought its robot, twice as many parts are machined every day. CNC machining takes the same amount of time, but the number of hours available now doubles the shop’s productivity. The company has been able to save half the time in production by eliminating a lot of machine idle time.

The contract in question needs to be completed within two months, so there is a rush to be able to deliver all the parts on time. A huge benefit when integrating a robot in the production line is that the machine can run non-stop in this two month period.

Caughey does not need to worry about training, extra salary, or employee retention between production rushes.

He had been stressed about production quality and consistency during unattended hours, too, but now realizes, “it's just about letting it go and accepting the fact that it's going to run for an extra 4-6 hours, that you're going to go home and nothing's going to break. And, that’s actually the case!”

Also, Arthur allows long-time machinist Matthew Niemeyer to improve his skillset on the production floor. “First, I got to learn how to program the robot,” Niemeyer explained. “Then, you have the robot loading the machine, but you're still doing all the fine-tuning of it, such as the programming. But, the remedial tasks of loading and unloading the machine are taken care for you, so you don't get worn out.”

When everything in the shop is running fine, Caughey is able to focus on his new role as a sales representative in the team. “We can get more and more business into the shop, which will lead to more machines, more robots, and promising overall growth.”

All of this wouldn’t be possible without the first robot. Far from eliminating jobs, Caughey believes that in the near future every small shop like his will have at least one robot. “No one is yelling at a contractor for using an excavator instead of hundred men with shovels,” he reasoned. “I didn’t fire anyone to do this. It just changes where the work is done. Instead of having guys sitting here putting parts in and taking parts out of the machine, they can do more quality-related stuff. They can check parts, clean, package them, and even bring in more sales.

And with a robot that doubles the production capacity, business opportunities are greater and orders are delivered on time. Foremost, with the satisfaction of WALT Machine’s first integration project, they see these new business opportunities as a way to scale their robotics capabilities in their shop.

No Robot Expertise and No Problem — Robotic automation may be intimidating for someone who has never touched a robot. Caughey is one of those entrepreneurs who started from scratch with his first robot. “I've programmed CNC machines and G-codes for 10 years, done XYZ positional and spatial stuff, but never explored robotics. When I got the robot, I did a little reading and it was pretty simple.”

As for the vision system, Caughey was impressed by the Robotiq Wrist Camera teaching methods. “You take your part and set it on the surface where you want it to be picked up, and you take four snapshots of it in four different orientations. Or, if it’s something simple, like a rectangular or a circular blank, you just set the dimensions of what you are picking and it knows.”

The next step is to put 15 to 20 of the same un-machined parts on the table within the camera’s field of view. The robot then rotates and looks over the table, takes one snapshot to see all the parts.

For more accurate picking, the robot gets closer and takes another snapshot of the part it is about to pick. After that, the robot places the part into the vice in the CNC machine. Then, it sends a signal to the Haas CNC machine to press the start button.

“It is so easy,” Caughey added. “We don't even have to teach waypoints because it only needs to look on this table for parts. We don't need a conveyor or any special fixturing. If you change parts, you just need to tell Arthur that you are looking for a different part, and change the two-finger gripper’s closing set-up. It's pretty simple. There isn't a lot of changeover, so that's why I like the camera-gripper combo.”